1. Field of the Invention
The present invention relates to a method and an apparatus for carrying out color correction processing on digital image data obtained by a digital camera. The present invention also relates to a computer-readable recording medium storing a program to cause a computer to execute the color correction method.
2. Description of the Related Art
In a digital still camera (hereinafter called digital camera), an image obtained by photographing is recorded as digital image data in an internal memory installed in the camera or in a recording medium such as an IC card, and the image can be displayed by using a monitor or a printer based on the recorded digital image data. When an image obtained by a digital camera is printed, the image is expected to have as high a quality as a photograph generated from a negative film.
Meanwhile, in the field of printing, a system for outputting an image as a hard copy from a printer by reading a color image with a scanner to obtain input image data and by carrying out a desired kind of image processing on the input image data to generate output image data has been put into practice (Japanese Unexamined Patent Publication No. 11(1999)-234523, for example) In such a system, the input image data are converted from RGB color signals into CMYK dot % signals. First, a tone curve (a tone conversion table) and a color correction amount used in a color correction unit are set for the input image data, and a three-dimensional look-up table (hereinafter called 3DLUT) for converting the input image data into the output image data is generated based on the tone curve and the color correction amount that have been set. The RGB color signals of the input image data are converted into the CMYK dot % signals of the output image data by interpolating the 3DLUT. Printing is carried out by controlling an amount of ink of each color by the dot % signal.
In such a system, the color correction amount is set so that lightness, chroma and hue of specific colors (such as C, M, Y, and K) in an image become appropriate. By setting the color correction amount, the specific colors in the image after the color correction have appropriate lightness, chroma and hue.
Meanwhile, color correction is also carried out when image data obtained by a digital camera are printed. Appropriate correction of the lightness, the chroma and the hue of the specific colors is also expected from this color correction, as from the color correction by the system for printing.